Surface air temperature distribution over the Ganges Delta Region of southwest Bangladesh and its tendency of warming are discussed through the analyses based upon the long-term temperature data from 1900-93. The data consist of two parts corresponding to the time-periods: 1973-93 and 1900-72. The study area is one of most affected places by the annual monsoon hydrological cycle and the present observation from these temperature data indicate that the surface air temperature gradient in the north-south direction is significant in the rainy season and that the temperature of the region is at an increasing tendency; the warming rate during the data periods (1900-93) on the long-term mean annual basis is estimated as 0.77℃ at Satkhira of the Khulna division and 0.29℃ as an areal average including the Barisal division, for the time difference of about half a century between the data periods before and after 1972